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1.
PLoS One ; 19(5): e0300451, 2024.
Article in English | MEDLINE | ID: mdl-38739643

ABSTRACT

PURPOSE: The aim of this study was to evaluate the imaging capabilities of Butterfly iQ with conventional ophthalmic (piezoelectric) ultrasound (COU) for ophthalmic imaging. METHODS: Custom phantom molds were designed and imaged with Butterfly iQ and COU to compare spatial resolution capabilities. To evaluate the clinical imaging performance of Butterfly iQ and COU, a survey containing pathological conditions from human subjects, imaged with both Butterfly iQ and COU probes, was given to three retina specialists and graded on image detail, resolution, quality, and diagnostic confidence on a ten-point Likert scale. Kruskal-Wallis analysis was performed for survey responses. RESULTS: Butterfly iQ and COU had comparable capabilities for imaging small axial and lateral phantom features (down to 0.1 mm) of high and low acoustic reflectivity. One of three retina specialists demonstrated a statistically significant preference for COU related to resolution, detail, and diagnostic confidence, but the remaining graders showed no significant preference for Butterfly iQ or COU across all sample images presented. CONCLUSION: The emergence of portable ultrasound probes offers an affordable alternative to COU technologies with comparable qualitative imaging resolution down to 0.1 mm. These findings suggest the value to further study the use of portable ultrasound systems and their utility in routine eye care.


Subject(s)
Phantoms, Imaging , Ultrasonography , Humans , Ultrasonography/methods , Ultrasonography/instrumentation , Eye Diseases/diagnostic imaging
2.
Cureus ; 15(6): e40527, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37461783

ABSTRACT

Age-related macular degeneration (AMD) is a disease that worsens the central vision of numerous individuals across the globe. Ensuring that patients are diagnosed accurately and that their symptoms are carefully monitored is essential to ensure that adequate care is delivered. To accomplish this objective, retinal imaging technology is necessary to assess the pathophysiology that is required to give an accurate diagnosis of AMD. The purpose of this review is to assess the ability of various retinal imaging technologies such as optical coherence tomography (OCT), color fundus retinal photography, fluorescein angiography, and fundus photography. The statistical methods that were conducted yielded results that suggested that using OCT in conjunction with other imaging technologies results in a higher detection of symptoms among patients that have AMD. Further investigation should be conducted to ascertain the validity of the conclusions that were stated within the review.

3.
Nutrients ; 15(5)2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36904116

ABSTRACT

Packed school lunch consumption remains a sparsely studied aspect of childhood nutrition. Most American research focuses on in-school meals provided through the National School Lunch Program (NSLP). The wide variety of available in-home packed lunches are usually nutritionally inferior compared to the highly regulated in-school meals. The purpose of this study was to examine the consumption of home-packed lunches in a sample of elementary-grade children. Through weighing packed school lunches in a 3rd grade class, mean caloric intake was recorded at 67.3% (32.7% plate waste) of solid foods, while sugar-sweetened beverage intake reported a 94.6% intake. This study reported no significant consumption change in the macronutrient ratio. Intake showed significantly reduced levels of calories, sodium, cholesterol, and fiber from the home-packed lunches (p < 0.05). The packed school lunch consumption rates for this class were similar to those reported for the regulated in-school (hot) lunches. Calories, sodium, and cholesterol intake are within childhood meal recommendations. What is encouraging is that the children were not "filling up" on more processed foods at the expense of nutrient dense foods. Of concern is that these meals still fall short on several parameters, especially low fruit/vegetable intake and high simple sugar consumption. Overall, intake moved in a healthier direction compared to the meals packed from home.


Subject(s)
Diet , Food Services , Child , Humans , Lunch , Energy Intake , Nutrients , Sodium
4.
Arch Ration Mech Anal ; 246(1): 1-60, 2022.
Article in English | MEDLINE | ID: mdl-36164458

ABSTRACT

We show that the local density of states (LDOS) of a wide class of tight-binding models has a weak body-order expansion. Specifically, we prove that the resulting body-order expansion for analytic observables such as the electron density or the energy has an exponential rate of convergence both at finite Fermi-temperature as well as for insulators at zero Fermi-temperature. We discuss potential consequences of this observation for modelling the potential energy landscape, as well as for solving the electronic structure problem.

5.
Opt Express ; 28(4): 4550-4562, 2020 Feb 17.
Article in English | MEDLINE | ID: mdl-32121689

ABSTRACT

The development of a broadly and accurately tunable single-frequency mid-infrared laser source and its application to a sensitive laser absorption detection method are described. Photo-thermal interferometric spectroscopy is employed as a phase-sensitive method to detect the minute refractive index change caused by the heating of a gas under laser radiation. A separate probe beam allows for the spectrally-interesting mid-infrared region to be examined whilst utilizing low cost, high detectivity photodetectors in the visible/near-infrared region. We also describe the implementation of a Sagnac interferometer to minimize the effects of environmental perturbation and provide inherent passive stability. A continuous-wave ring-cavity pump-enhanced OPO has been developed to provide excitation light from 3-4 µm at 140 mW with the ability to mode-hop tune continuously over 90 cm-1 in 0.07 cm-1 steps. Complementary use of both detection apparatus and excitation source has allowed for presence of ethane to be detected down to 200 parts per billion.

6.
J Med Chem ; 62(19): 8796-8808, 2019 10 10.
Article in English | MEDLINE | ID: mdl-31497959

ABSTRACT

The heterodimeric transmembrane αv integrin receptors have recently emerged as potential targets for the treatment of idiopathic pulmonary fibrosis. Herein, we describe how subtle modifications of the central aromatic ring of a series of phenylbutyrate-based antagonists of the vitronectin receptors αvß3 and αvß5 significantly change the biological activities against αvß6 and αvß8. This resulted in the discovery of a pan αv antagonist (compound 39, 4-40 nM for the integrin receptors named above) possessing excellent oral pharmacokinetic properties in rats (with a clearance of 7.6 mL/(min kg) and a bioavailability of 97%).


Subject(s)
Idiopathic Pulmonary Fibrosis/pathology , Integrin alphaV/chemistry , Phenylbutyrates/chemistry , Administration, Oral , Animals , Antigens, Neoplasm/metabolism , Binding Sites , Crystallography, X-Ray , Drug Evaluation, Preclinical , Half-Life , Humans , Idiopathic Pulmonary Fibrosis/drug therapy , Idiopathic Pulmonary Fibrosis/metabolism , Integrin alphaV/metabolism , Integrin alphaVbeta3/antagonists & inhibitors , Integrin alphaVbeta3/metabolism , Integrins/antagonists & inhibitors , Integrins/metabolism , Molecular Conformation , Molecular Docking Simulation , Phenylbutyrates/pharmacokinetics , Phenylbutyrates/therapeutic use , Protein Structure, Tertiary , Rats , Receptors, Vitronectin/antagonists & inhibitors , Receptors, Vitronectin/metabolism , Structure-Activity Relationship
7.
Mult Scler ; 24(1): 6-11, 2018 01.
Article in English | MEDLINE | ID: mdl-29307295

ABSTRACT

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) and a major contributor to disability of young adults in western countries. MS prevalence is highest in areas with low vitamin D. Vitamin D is a fat-soluble compound with numerous physiologic responses, including immune regulation. An increasing volume of work suggests that lower levels of serum vitamin D are associated with an increased risk of MS and a more severe disease course. With the suggestion of a role in MS disease activity, increasing attention is being paid to the potential of using vitamin D as an add-on therapy to established MS disease-modifying therapies. Several preliminary studies have reported results which have shown some promise, but none has yet provided significant evidence of a clinically meaningful improvement. We review our recommendations for off-label supplementation in the context of these findings.


Subject(s)
Dietary Supplements , Multiple Sclerosis , Vitamin D , Humans
9.
Plast Reconstr Surg ; 138(1): 82e-90e, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27348689

ABSTRACT

BACKGROUND: Mandibular distraction is effective for relieving airway obstruction in Robin sequence; however, mid-term dental and nerve-related complications have not been adequately studied. METHODS: Records were reviewed for patients with a single distraction in infancy using internal devices. Follow-up was 5 years or longer. Craniofacial dysmorphic syndromes and those affecting facial nerve function were excluded. Part I involved a review of dental records, whereas Part II involved assessment of inferior alveolar and marginal mandibular nerve function in returning patients with the use of 1,1,1,2-tetrafluoroethane cold stimulation and photography, respectively. RESULTS: Eighty-five patients met inclusion criteria. Dental records were complete in 44 patients (median follow-up, 7.3 years; range, 5.4 to 13.2 years). First permanent molar injury was seen in 42 of 88 half-mouths (48 percent); 32 of 42 (76 percent) were restorable. Primary second molar damage and ankylosis were observed in 12 of 88 (14 percent) and one of 88 half-mouths (1 percent), respectively. Mandibular second premolar absence was noted unilaterally in eight of 36 patients (22 percent) and bilaterally in six of 36 patients (17 percent). A mean 1.2 ± 0.95 operative rehabilitations were required. Nerve testing was completed in 20 patients (median follow-up, 8.7 years; range, 5.5 to 13.2 years). Complete absence of cold sensation was noted in one of 40 half-mouths (2.5 percent), whereas lower lip depressor weakness was seen in six of 40 half-mouths (15 percent). CONCLUSIONS: Infant distraction is highly successful in averting tracheostomy; however, dental and nerve-related complications remain underreported. Regular follow-up with a pediatric dentist and early recognition of injury is essential. Although inferior alveolar nerve injury appears infrequent (2.5 percent), permanent lower lip depressor weakness is more common than previously reported (15 percent of sides). CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Subject(s)
Airway Obstruction/surgery , Mandible/surgery , Osteogenesis, Distraction/adverse effects , Pierre Robin Syndrome/surgery , Postoperative Complications , Tooth, Deciduous/innervation , Adolescent , Airway Obstruction/etiology , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Male , Photography , Pierre Robin Syndrome/complications , Retrospective Studies , Time Factors , Treatment Outcome , Video Recording
10.
Cardiovasc Revasc Med ; 15(1): 18-22, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24315045

ABSTRACT

BACKGROUND: The Cobra-P drug-eluting stent (DES) system consists of cobalt chromium alloy with bio-absorbable siloxane sol-gel matrix coating that elutes low dose paclitaxel within 6 months. The aim of this first-in-man trial was to evaluate the safety and performance of 2 doses of the Cobra-P DES. METHODS: A total of 60 lesions (54 patients) were sequentially assigned to 2 different paclitaxel doses: group A (3.7 µg/18mm, n=30) or group B (8 µg/18mm, n=30). The primary endpoint was MACE at 4 months defined as cardiac death, myocardial infarction, and target lesion revascularization. RESULTS: Patient and lesion characteristics were matched between the 2 groups except for male sex. MACE at 4 months was 3.3% and 0% respectively (P=1.000) and at 1-year follow-up remained unchanged. In-stent late loss at 4 months was similar in both groups (0.36 ± 0.30mm and 0.34 ± 0.20mm P=.773). CONCLUSIONS: In this FIM study, implantation of the Cobra-P low dose paclitaxel-eluting stent with a bioabsorbable sol-gel coating was proven to be feasible and safe. Moderate neointimal proliferation was observed as well as an acceptable MACE rate up to 1 year.


Subject(s)
Absorbable Implants , Cardiovascular Agents/administration & dosage , Coated Materials, Biocompatible , Coronary Artery Disease/therapy , Drug-Eluting Stents , Paclitaxel/administration & dosage , Percutaneous Coronary Intervention/instrumentation , Aged , Cell Proliferation , Coronary Angiography , Coronary Artery Disease/diagnosis , Coronary Restenosis/etiology , Feasibility Studies , Female , Humans , Male , Middle Aged , Neointima , Percutaneous Coronary Intervention/adverse effects , Prosthesis Design , Time Factors , Treatment Outcome
11.
J Vasc Interv Radiol ; 21(5): 627-37, 2010 May.
Article in English | MEDLINE | ID: mdl-20304680

ABSTRACT

PURPOSE: This registry was designed to evaluate the Bridge Extra Support renal stent system (Medtronic, Santa Rosa, California) in the treatment of renal artery ostial lesions following suboptimal percutaneous transluminal renal angioplasty (PTRA). MATERIALS AND METHODS: This consecutive, nonrandomized, prospective, multicenter registry enrolled 188 patients between April 1999 and May 2002 with single de novo or restenotic renal artery ostial lesions (>or=70% stenosis) who underwent implantation of a balloon-expandable stent immediately following unsuccessful PTRA. Primary safety endpoints were major adverse clinical events (MACE) at 30 days and 9-12 months. The primary efficacy endpoint was absence of binary restenosis at 9-12 months with duplex ultrasonography (US). Secondary endpoints were acute success and quality-of-life (QOL) improvements (blood pressure, antihypertensive medications, renal function). The long-term effect of renal artery stenting on blood pressure and renal function was assessed to 36 months. RESULTS: The acute procedure and clinical success rates were 92.9%. At 30 days, the MACE rate was 3.2%, with no instances of target lesion revascularization (TLR). At 9-12 months, the MACE rate was 16.5%, with five (2.7%) deaths and 14 (7.4%) instances of TLR. The rate of restenosis at 9-12 months with duplex US was 12.6%, and 94% of patients had QOL improvements. A significant reduction in systolic blood pressure occurred following renal artery stenting and persisted to 36 months. CONCLUSIONS: Renal artery stenting is safe and efficacious in the treatment of single de novo and restenotic renal artery ostial lesions following suboptimal PTRA.


Subject(s)
Graft Occlusion, Vascular/etiology , Graft Occlusion, Vascular/prevention & control , Renal Artery Obstruction/surgery , Renal Artery/diagnostic imaging , Renal Artery/surgery , Stents/adverse effects , Adult , Aged , Aged, 80 and over , Female , Graft Occlusion, Vascular/diagnostic imaging , Humans , Male , Middle Aged , Radiography , Registries , Renal Artery Obstruction/complications , Renal Artery Obstruction/diagnostic imaging , Treatment Outcome , United States
12.
J Am Diet Assoc ; 110(4): 608-12, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20338287

ABSTRACT

Bariatric surgery forces participants to undergo a volatile dietary adjustment. The purpose of this cross-sectional research was to chronicle food selection during the period from when solid food is reintroduced through 2.5 years. Forty-eight postsurgery Roux-en-Y gastric bypass patients participated in the research. Each food item selection was recorded from a list of foods that consisted of 236 individual foods. Food item selection was then categorized into one of nine conventional US Department of Agriculture-based food-groupings (eg, Dairy). No food selection differences were detected between the men and women in the study. Mean weight loss since surgery was 53.6+/-20.6 kg. Mean time since surgery was 11.1+/-7.0 months for the 35 female and 13 male patients. The food selection categories ranged from 63.2% for Condiments to 28.3% for Sweets. Next, food selections were reclassified into 31 more specific bariatric subgroups (eg, Cheeses, Milks, Yogurts). Bariatric subgroup intake ranged from 84.2% for Bottled/Tap Water to 4% for Sugared Beverages. Several group homogeneity differences existed between conventional and bariatric subgroups. Subgroup means were statistically different for the conventional categories of Dairy, Sweets, and Beverages (P>0.05). These differences demonstrate that the standard benchmarks of conventional food groupings sometimes fail to represent accurately food selection in this population. This type of more specific classification information improves eating recommendations provided by dietetics practitioners. Just as exchange food groups are of great value to patients with diabetes, these more specific bariatric food subgroups represent a needed increase in accuracy in dietary recommendations for patients after Roux-en-Y gastric bypass.


Subject(s)
Feeding Behavior , Gastric Bypass , Obesity, Morbid/surgery , Weight Loss/physiology , Adult , Choice Behavior , Cross-Sectional Studies , Diet Surveys , Female , Follow-Up Studies , Food Preferences , Gastric Bypass/adverse effects , Humans , Male , Patient Education as Topic , Postoperative Period
13.
J Food Prot ; 72(8): 1713-7, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19722406

ABSTRACT

The present study examined the incidence of Escherichia coli O:H7 and Salmonella in feedlot lambs. Fifty-six feedlot lambs from eight sheep farming operations were grouped in a single drylot pen, fed, and managed as is typical in the southwestern United States. Fecal samples were collected on days 0, 46, 87, and 122 of the feeding period via rectal palpation. Wool samples (ventral midline) were collected one time only at the feedlot, immediately prior to shipping to the processing plant, and carcass swabs were collected following slaughter. All samples were cultured for E. coli O157:H7, Salmonella, and fecal coliforms, and select isolates were examined for antimicrobial susceptibility. Overall, the percentages of fecal and wool samples positive for E. coli O157:H7 averaged 9 and 18%, respectively. One carcass swab was E. coli O157:H7 positive. Of the 155 fecal samples collected, 11 (7%) were Salmonella positive. Salmonella was detected in nearly 50% of the wool samples collected prior to slaughter, while none of the carcasses were Salmonella positive 24 h postslaughter. All isolates (E. coli O157:H7, Salmonella, and fecal coliforms) were susceptible to ceftiofur, enrofloxacin, and trimethoprim-sulfamethoxazole. One E. coli O157:H7 isolate cultured from a carcass swab was resistant to seven antibiotics, and seven wool E. coli O157:H7 isolates were multidrug resistant. Results of this research demonstrate that feedlot sheep are naturally colonized with E. coli O157:H7 and Salmonella and wool can be a source of carcass contamination; however, in-plant processing procedures and intervention strategies were largely effective in preventing carcass contamination.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Escherichia coli O157/drug effects , Salmonella/drug effects , Sheep/microbiology , Animals , Animals, Newborn , Colony Count, Microbial , Drug Resistance, Multiple, Bacterial , Feces/microbiology , Food Contamination/prevention & control , Microbial Sensitivity Tests , Prevalence , Salmonella/isolation & purification , Wool/microbiology
14.
Clin Linguist Phon ; 23(5): 335-47, 2009 May.
Article in English | MEDLINE | ID: mdl-19399666

ABSTRACT

Although perceptual studies indicate the likelihood of voice disorders in persons with stroke, there have been few objective instrumental studies of voice dysfunction in dysarthria following stroke. This study reports automatic analysis of sustained vowel phonation for 61 speakers with stroke. The results show: (1) men with stroke and healthy elderly men exhibited an identical voice profile, and men with stroke had only one significantly larger noise parameter (SPI--soft phonation index) than young healthy men; and (2) women with stroke and healthy elderly women exhibited an identical voice profile, except that women with stroke exhibited a significantly higher SPI than healthy elderly women. Although there were no significant differences in smoothed pitch perturbation quotient (sPPQ) and SPI between healthy elderly women and healthy young women, women with stroke exhibited significantly larger sPPQ and SPI than healthy young women. It is suggested that studies on sub-groups of the stroke population that use a combination of perceptual and acoustic analyses will better illuminate the voice dysfunction in dysarthria following stroke.


Subject(s)
Dysarthria/etiology , Speech Acoustics , Speech , Stroke/complications , Adult , Aged , Aged, 80 and over , Aging , Dysarthria/psychology , Female , Humans , Male , Middle Aged , Software , Speech Production Measurement , Voice , Young Adult
15.
Folia Phoniatr Logop ; 61(1): 1-11, 2009.
Article in English | MEDLINE | ID: mdl-19088478

ABSTRACT

AIMS: The Diadochokinetic Rate Analysis (DRA) in the KayPENTAX Motor Speech Profile is a computer program for the analysis of diadochokinesis (DDK). The objective of this study is to evaluate the suitability, reliability, and concurrent validity of the results from the DRA protocol and hand measurement for individuals with ataxic dysarthria, which is characteristically associated with dysdiadochokinesis. METHODS: Twenty-one participants with ataxic dysarthria were recorded as they repeated various syllables as quickly and steadily as possible. The DDK samples were executed by the DRA protocol at different thresholds and were also hand-measured. Analyses were based on the percentage of nonexecutable DDK samples, defined as samples in which the lowest peak intensity during CV syllables is lower than the highest peak intensity during intersyllable pauses, and the comparisons of the results between repeated analyses at different thresholds and between automatic and manual measuring methods. RESULTS: (1) More than one third of the DDK samples were nonexecutable; (2) the reliability at different thresholds and concurrent validity between different measuring methods were both satisfactory, and (3) temporal variation parameters were more inconsistent between different measuring methods than intensity variation parameters. CONCLUSION: DRA has notable limitations in its clinical application but there is a considerable potential for improving its performance.


Subject(s)
Dysarthria/psychology , Speech Production Measurement/methods , Speech , Adolescent , Adult , Aged , Dysarthria/physiopathology , Female , Humans , Male , Middle Aged , Psychomotor Performance , Reproducibility of Results , Software , Sound Spectrography , Time Factors
16.
Obes Surg ; 18(3): 282-7, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18214629

ABSTRACT

BACKGROUND: This research compared both food selection and food intolerance frequency of High-fat grouped foods versus Low-fat grouped foods in Roux-en-Y bariatric clients during their dietary adaptation phase (DAP). METHODS: Thirty-eight bariatric surgery patients in their dietary transition phase (3 months-2.5 years) filled out a 236-food item questionnaire. From the larger set of primary data, 24 high-fat (30% or greater fat) and 22 low/lower-fat food items were itemized by selection frequency and food intolerance frequency for comparison. RESULTS: High-fat food selection was 38.3% against low fat at 50.4% (p = .0002). For comparison, the complete questionnaire's 236-item food selection percentage was 41%. Frequency of "Never" experiencing food intolerance was similar between both groups with a combined mean of 1.92%. "Seldom to Sometimes" intolerance in low-fat foods was 13.3%, and 24.9% in high fat (p = .002). Finally, "Often to Always" experiencing food intolerance in the Low-fat food group was 85.5% versus 72.2% for the High-fat group (p = .002). CONCLUSION: Roux-en-Y bariatric patients in the DAP demonstrated typical "dieting behavior" by selecting low-fat foods at a greater frequency than high-fat foods. Although selected more, these low-fat foods also showed significantly worse intolerance frequencies. Thus, current dietary/nutrition professional recommendations to avoid high-fat foods during this postsurgery transition time are problematic. Future bariatric studies are needed to further explore this and other commonly practiced "dieting behaviors" in bariatric patients.


Subject(s)
Dietary Fats/adverse effects , Food Preferences , Gastric Bypass , Obesity, Morbid/surgery , Adaptation, Physiological , Adult , Female , Humans , Male , Weight Loss
18.
Conserv Biol ; 20(2): 277-87, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16903089

ABSTRACT

In the 1990s the federal forests in the Pacific Northwest underwent the largest shift in management focus since their creation, from providing a sustained yield of timber to conserving biodiversity, with an emphasis on endangered species. Triggered by a legal challenge to the federal protection strategy for the Northern Spotted Owl (Strix occidentalis caurina), this shift was facilitated by a sequence of science assessments that culminated in the development of the Northwest Forest Plan. The plan, adopted in 1994, called for an extensive system of late-successional and riparian reserves along with some timber harvest on the intervening lands under a set of controls and safeguards. It has proven more successful in stopping actions harmful to conservation of old-growth forests and aquatic systems than in achieving restoration goals and economic and social goals. We make three suggestions that will allow the plan to achieve its goals: (1) recognize that the Northwest Forest Plan has evolved into an integrative conservation strategy, (2) conserve old-growth trees and forests wherever they occur and (3) manage federal forests as dynamic ecosystems.


Subject(s)
Conservation of Natural Resources/legislation & jurisprudence , Conservation of Natural Resources/methods , Ecosystem , Forestry/history , Trees , Forestry/legislation & jurisprudence , History, 20th Century , History, 21st Century , Northwestern United States
20.
Ecol Appl ; 16(4): 1529-38, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16937816

ABSTRACT

Populations of Greater Sage-Grouse (Centrocercus urophasianus) have declined by 69-99% from historic levels, and information on population dynamics of these birds at a landscape scale is essential to informed management. We examined the relationships between hen survival and a suite of landscape-scale habitat and environmental conditions. We radio-marked 237 female Sage-Grouse and measured 426 vegetation plots during 2001-2004 at four sites in a 3200-km2 landscape in north-central Montana, USA. We used program MARK to model monthly survival rates for 11 seasonal intervals. There was strong support for the best-approximating model (AICc weight = 0.810), which indicated that (1) hen survival varied by season within years and by year within seasons, (2) nesting hens had higher nesting-season survival than non-nesting hens, and (3) individuals at one site had lower hunting-season survival than at other sites. We observed considerable variation in hen survival. Process variation was 0.255, with an expected range of annual survival of 0.12 to 1.0. The ratio of process to total variation was 0.999, indicating that observed variation was real and not attributable to sampling variation. We observed a nearly fourfold difference in maximum and minimum annual survival, ranging from 0.962 +/- 0.024 (mean +/- SE) for nesting hens in 2001-2002 to 0.247 +/- 0.050) for non-nesters in 2003-2004. Low annual survival in 2003 resulted from the compounded effects of a West Nile virus outbreak in August and a severe winter in 2003-2004. Increased hen mortality associated with severe winter weather contrasts with prior beliefs that Sage-Grouse populations are typically unaffected by winter weather conditions and underscores the importance of protecting winter sagebrush (Artemisia spp.) habitats.


Subject(s)
Galliformes/physiology , Animals , Female , Models, Biological , Montana , Population Dynamics , Seasons , Survival Rate , Time Factors
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